Tape recorder and offset playback apparatus with a variable tape length between the recording and reading head

ABSTRACT

A recording head (9) and a playback head (8) each provided with a separate actuating device, a storage hopper (33) between the heads (8, 9) receives the tape (2) fed out by the recording head (9) and stores in loose, random folds when the tape region facing the recording head (9) is at a distance from the tape region facing the reading head (8), two reels interacting with respective heads are arranged in a cassette (1), when the cassette is inserted, a roller (3) grips the tape and pre-engages it into the storage hopper (33), which apparatus enables time-delay playback without causing undesirable congestion or tape installation problems.

This invention relates generally to an apparatus for recording on andplaying back a tape which is capable of being recorded on and playedback such as a video-tape recorder or tape recorder.

Commercially available apparatuses of this type include a single headcarrier mechanism on which are located both the means of recordingelectrical signals on a magnetic tape and the means of reproduction byplaying back signals of this type.

During the recording operation the tape is brought into contact with thehead carrier and the signals are applied to the head.

During the reverse operation, i.e. during playback the tape is againbrought into contact with the head carrier. The recorded messages areanalysed by the head or the heads so as to reconstitute the video oraudio signals which have been recorded previously.

The recording and playback functions are independent of each other.

In addition this type of apparatus includes two reels which arefrequently grouped together in a cassette and each of which receives thetape over a certain length from one of its ends respectively. Therotational speeds of these two reels are controlled in relation to eachother.

This applies both to sound recordings and to recordings of images.

The disadvantage of these apparatuses is that recordings on the tape orthe playing back of the tape cannot be carried out simultaneously andindependently of each other. Consequently he can reproduce it in full.In other words the user is not able to play back the beginning of thisrecording during the recording process.

According to the document EDN ELECTRICAL DESIGN NEWS, Vol.8, No.9,August 1963, Newton, Mass., pages 18-21 a recording and playbackapparatus for information data is known which includes two sets ofrecording and reading heads and a reel for each set of heads. There is astorage hopper to receive a certain length of tape and to store it inloose and random folds when one of the sets of heads is used for exampleto playback with a constant delay what has been recorded or to recordand playback at different speeds. The two reels are controlledindependently of each other as well as the two sets of heads. Concerninga simultaneous effect playback structure, the playback reel can be knownas the reel on which the tape is wound in during a normal playbackoperation and the recording reel can be known as the reel from which thetape is fed out towards the head carrying out the recording.

According to this document this apparatus is used above all to processinformation data recorded on tape with a certain delay between therecording and the playback.

This known apparatus is cumbersome as it is necessary for the tape to berun from the recording reel to the recording head and then to theintermediate storage hopper after which it runs to the reading head soas to arrive finally at the playback reel not to mention the guidemechanisms for the tape according the variable paths.

The result of this is that the known apparatus is in the form of a wallcabinet.

U.S. Pat. No. 28.461 describes an apparatus for playing back a cassettein which from each side of the reading head the tape is run in a suctionwell. A special means is provided to bring a loop of tape from thecassette to the entry of each well. The object of these wells is toregulate the tension of the tape. The two reels rotate whenever theapparatus is used.

In addition apparatuses are known in accordance with U.S. Pat. No.4,388,659 and WO-A-90/00800 which have substantially the same object asthe EDN document but which appear to be not only cumbersome but alsohighly complex with storage which at least in part is ordered inrelation to the tape between the recording head and the reading head.

Patent specification WO-A-90/00800 claims to provide the general publicwith the means of recording on and playing back a tape with the twoprocesses being independent of each other. This document, however,recommends that the tape be left permanently in the apparatus somethingwhich is contrary to the requirements of the general body of users wholike to have a recordings library.

According to patent specification JP-A-4 104 678 a cassette apparatus isalso known with which simultaneous offset playback can be carried outand which is provided with a recording head, a reading head and astructure for storing a recorded part of the tape between the heads.This apparatus, however, does not have the means for carrying out anunwinding of the recorded tape in reverse from the playback reel towardsthe storage hopper. The user does not have the facilities provided byconventional tape recorders and videotape recorders. He is also unableto carry out a fast or slow search in reverse either with or withoutplayback whilst continuing the recording.

On all the known apparatuses with which simultaneous offset playback canbe carried out the installation of the tape is either not specified ormade very complex by the use of intermediate storage. The fact that inthe W0-A-90/00800 specification it is recommended not to change the tapeis an indication of the prominence of this feature.

The object of this invention is therefore to create an apparatus whichmakes simultaneous offset playback possible and which is arranged insuch a way that it is entirely compatible with the requirements of thegeneral public as far as cost, space required and method of use areconcerned.

According to the invention the apparatus which makes possible therecording and simultaneous or simultaneous offset playback of arecording tape such as a tape of a video-tape recorder or a taperecorders, comprising a recording head, means for making the tapecirculate in front of the recording head towards and from a recordingreel respectively, a reading head, means to make the tape circulate infront of the reading head towards and from a playback reel respectively,both the heads being provided with means making it possible to actuatethem independently of each other, and in addition a storage hopperlocated operatively between the two heads so as to receive a part of thetape and to store it when the tape region facing the reading head is ata distance from the tape region facing the recording head, and the saidapparatus including fitting means for a cassette with two reels each ofwhich is associated with one of the ends of the tape so that therecording and reading heads are arranged so that each one cooperateswith one of the reels of the cassette with one of them constituting inoperation the recording reel and the other the playback reelrespectively, is characterized in that the apparatus also includes meansfor bringing the tape into position in relation to the storage hopperafter the insertion of the cassette with the storage hopper storing thesaid tape in loose and random folds and in that the apparatus includesmeans for feeding the tape in a reverse movement in relation to thedirection of recording from the playback reel towards the storagehopper.

The invention combines the "ordered" arrangement represented by thecassettes with two reels with the "disorder" represented by storage inloose and random folds of a part of the tape which may be relativelylong.

By means of grouping the two reels together in a cassette which may be acassette of a format which is currently commercially available for aconventional apparatus, the use of the apparatus is considerablysimplified including its loading and unloading. The user does not evenhave to be concerned with the presence of the intermediate hopper,because the means for bringing the tape into position in relation to thehopper carry out the necessary positioning.

This invention makes it possible and in particular for ordinary domesticusers to have the facility of what is called here "simultaneous offsetplayback" which consists of being able, when a recording is in progress,of playing back the same tape at any point whatever between itsbeginning and the recording point. It is possible to have the tapeopposite the reading head move backwards without interrupting therecording process.

The user is also able to effect a rapid playback of the recorded portionso as, where applicable, to make up the time by rapidly passing over thesections in which he is not interested so as to finish up by followingthe programme live.

The apparatus according to the invention can also be used as a normalapparatus and is provided for this purpose with a rapid advance andreturn movement. It can be used for playing back alone or recordingalone and in the case of a video-tape recorder with a freeze-frame.

It has been found possible to set down a tape in loose folds in a randommanner in a rectangular case if this tape is prevented from resting onthe side. For this purpose a hopper is used which has the same width asthe tape and means are used to prevent it from lying on the side. Thisis preferably achieved by disposing the hopper in a vertical position soas to make use of the force of gravity but it can also be achieved byblowing or suction or any other similar means. It has been found inpractice that in this way it is possible to have the recording reel fedinto the hopper without extracting it by means of the other reel; thetape is laid in superimposed or juxtaposed folds in a random manner andwithout forming knots. It is then possible whilst allowing the feedingof the recording coil to take place to operate the playback reel whichstill extracts the tape without forming knots. The playback tape caneven be operated in reverse in such a way that the two reelssimultaneously feed the hopper; during take up the tape portions areslid against each other and the folds are unravelled without gettingentangled.

The apparatus is preferably characterized in that it also includes rollswith which it is possible to move the tape of the playback reel towardsthe storage hopper at different speeds in reverse with or withoutplayback of the said tape.

The apparatus according to the invention is also distinctive in that:

the storage hopper is provided with an entry which is disposed betweenthe said reading and recording head carriers,

the storage hopper has in the direction of the width of the tape adimension which is equal to the width of the tape,

means are provided for detecting the exhausting of the reserve of tapein the hopper and independently or jointly means for drawing the tape ina loop towards the inside of the hopper from the situation in which acassette has just been inserted in the apparatus,

a tape tension detector is disposed between the two reels,

when the tape is stored in the hopper the detector is used to indicatethat the said storage hopper is empty when it is in contact with thetape,

the detector is composed of an idle roll which is displaced verticallyon a carriage so as to draw the tape in the operating position towardsthe inside of the storage hopper from the situation in which thecassette has just been inserted,

the guiding and drive mechanisms of the tape are made up of five rollsfor each of the two reels so that there are three idle rolls and twodrive rolls for the playback reel and three idle rolls and two driverolls for the recording reels,

when the tape is stored in the hopper the detector is used to indicatethat the said storage hopper is empty when it is in contact with thetape,

the detector is composed of an idle roll which is displaced verticallyon a carriage so as to draw the tape in the operating position towardsthe inside of the storage hopper from the situation in which thecassette has just been inserted,

the guiding and drive mechanisms of the tape are made up of five rollsfor each of the two reels so that there are three idle rolls and twodrive rolls for the playback reel and three idle rolls and two driverolls for the recording reel,

the idle rolls are either mounted on bars actuated by pivots or oncarriages which are displaced in slides according to the length ofdisplacement required to make them active,

the drive rolls of the playback reel do not rotate in the same directionwhereas the drive rolls of the recording reel rotate in the samedirection,

the hopper can include a relatively narrow entry/outlet openingassociated with means to guide a tape loop towards the inside of thehopper in such a way that the tape enters and leaves the hopper producedas a dead end between the recording head and the reading head.

The invention will be better understood on the basis of the followingdescription with reference to the figures which show, by way of anon-restrictive example, an apparatus designed for a video tape for avideo-tape recorder as follows:

FIG. 1 shows a sectional side view of a video-tape recorder according tothe invention;

FIG. 2 shows the drive mechanism of the video tape of the video-taperecorder of FIG. 1;

FIG. 3 shows a front view of the cassette carrier magazine and

FIG. 4 shows a front sectional view of the apparatus showing the storagehopper of the video tape.

As is shown in FIG. 1, the video-tape recorder includes apart fromcompartments 30 and 40 designed to contain the means of mechanical andelectronic control, a cassette carrier magazine 28 and a storage hopper33.

In this example the storage hopper 33 is disposed vertically in such away that the tape is laid down in loose folds by gravity. The invention,however, is not restricted to this special embodiment and instead ofusing gravitational force another force as for example a blowing orsuction force can be used.

As shown in FIG. 2 the drive mechanism of the video-tape recorderincludes two drive pins 4 and 5 of the playback reel 6 and the recordingreel 7 respectively, two video head carriers, a reading head carrier 8and a recording head carrier 9, passive idle rolls 10, 11, 12 and 13,active idle rolls 14, 15, 16, 17, 18, and 19 mounted either on a rod 26actuated by a pivot 27 for rolls 18 and 19 or on carriages 31 which aredisplaced in the slides 32 for rolls 14, 15, 16, and 17 and drive rolls20, 21, 22 and 23.

As can be more easily seen in FIG. 3, the storage hopper 33 has arelatively narrow upper entry disposed between the said reading headcarrier 8 and the said recording head carrier 9.

In the case of a video-tape recorder the recording and reading heads arethemselves mobile in such a way that the tape is applied against themover approximately 180° and they are then carried by mobile supportswhich will be known hereinafter as "head carriers".

The cassette I including, in a manner known in itself, the playback andrecording reels carrying the tape 2 is introduced manually into thecassette carrier magazine 28 and is fixed by means of the drive pins ofthe reels 4 and 5 and the passive idle rolls 10 and 11. The tapeprotector of cassette 1 opens and the tape 2 comes to be positioned at2a between the detector 3, occupying at that-time-position 3a (FIG. 2)and the passive rolls 12 and 13.

As can be seen from FIG. 3, the detector 3 is composed of an idle roll25 mounted vertically on a mobile carriage 24, thus transversally to thepath la of the tape. After the insertion of the cassette the carriage 24is displaced automatically so that the roll 25 draws the tape 2 towardsthe operating position represented by a full line in FIG. 2 as well asin FIG. 3. The tape is then held between the passive rolls 12 and 13 andthe detector 3, which makes the tape describe a pre-engagement loop inthe entry and exit orifice of the storage hopper (33). The hopper 33 isproduced as a dead end. It becomes considerably wider under heads 8 and9 (FIG. 4) whilst having everywhere a thickness corresponding to thewidth of the tape.

The function of the detector 3 is also to prevent the tape from breakingwhen the tape is taut and the playback reel is driven at a speed whichis greater than that of the feeding out of the recording reel. It ispreferable to use this detector but it is not essential. If the hopper33 is transparent the user can see the storage hopper being emptied andthe tape becoming taut between the rolls.

When recording in the conventional manner the playback reel 6 is activein being wound up and the recording reel 7 is active in being fed outwhilst the tape 2 is brought into contact with the drive roll 21 and therecording head carrier 9. This is obtained by actuating idle rolls 15,17 by displacing their respective carriages; on the other hand thereading head carrier 8, the drive rolls 20, 22 and 23 and the idle rolls14, 16, 18 and 19 are in the rest position.

During playback, i.e. when it is desired to display a previouslyrecorded cassette, the playback reel 6 is active in being fed out andthe recording reel 7 is active in being wound up whilst the tape 2 isbrought into contact with the reading head carrier 8 and the drive roll20 by the idle rolls 14 and 16. On the other hand the recording headcarrier 9, the idle rolls 15, 17, 18 and 19 and the drive rolls 21, 22and 23 are in the rest position.

During this playback alone, the user can carry out a rapid forwardmovement and the tape will still be in contact with the drive roll 20and the reading head carrier 8. He can also carry out a fast backreading during which the tape 2 will be in contact with the reading headcarrier 8 and the drive roll 22. In both cases the playback reel 6 andthe recording reel 7 will have variable winding up and feeding outspeeds.

During this conventional method of operating the videotape recorderrapid forward movements and rapid return movements can also be carriedout without playback or recording with the reading head carrier 8 andthe recording head carrier 9 being in the rest position.

During all these conventional applications of the videotape recorder thedrive speeds of the playback and recording reels are dependent on eachother, the hopper 33 continues to remain empty and the detector 3 is inpermanent contact with the tape 2.

According to the invention the video-tape recorder can also becontrolled in simultaneous offset playback. When this is done asrecording is still in progress by the head carrier 9 by means of thedrive roll 21 and the passive rolls 15 and 17, the playback reel 6 isput into the rest position and the drive roll 23 is made active by meansof the idle roll 19.

The roll 23 then draws the tape towards the storage hopper 33.Consequently as the recording is effected during which the tape 2 is inthe normal manner brought into contact with the drive rolls 21 and 23and the recording head 9 by means of the active idle rolls 15, 17 and 19the tape is not drawn towards the playback reel and falls into thestorage hopper 33.

During this storage of the tape the detector 3 is no longer in contactwith the said tape.

The simultaneous offset playback is put into operation by actuating theplayback reel 6 and by taking up the tape 2 again, stored in the hopper33 and brought into contact with the drive roll 20 and the reading headcarrier 8 by means of the idle rolls 14 and 16.

The user can carry out a part of this simultaneous offset playback in anaccelerated manner so as to make up the time and to follow the end ofthe programme live without having to interrupt the recording. When thisis done the tape 2 continues to be in contact with the reading head 8and the drive roll 20 which is then actuated rapidly by means of thedrive pin 4 of the playback reel 6 which has a variable windup modeaccording to a known process.

When the detector 3 is again in contact with the tape 2 which indicatesthat the hopper 33 is empty it stops the rapid playback so that the tape2 is not broken but permits a playback at normal speed.

Whilst still in this simultaneous offset playback mode the user cancarry out a reverse playback or a fast reverse playback. The tape 2 isthen brought into contact with the drive roll 22 which can be actuatedat rapid or normal speed and the reading head carrier 8 by means of idlerolls 16 and 18.

Finally still in simultaneous offset playback the user can carry out afast or normal speed forward movement and a fast or normal speed returnmovement without playback. The tape is then no longer in contact withthe reading head carrier 8 but is driven by the drive roll 22 by meansof the idle roll 18 in the case of a return movement and wound up byreel 6 by means of the drive pin 4 in the case of a forward movement.

In the example described in this way a detector 3 has been provided thefunction of which is to detect the tension of the tape so as to avoid abreak. It is not necessary however to fit a detector of this type and itis possible to fit a dynamometric device calibrated in relation to theresistance to traction of the tape on the roll 20 and the pin 4.

Above all however it is possible to position revolution counters on thedrive rolls so as to know the length of the tape in storage so that itis not only possible to avoid putting the tape in tension but also toknow the extent of the offset between recording and playback.

In practice it is preferable not to fill the storage hopper 33 when theapparatus is functioning durably solely in recording mode. Under theseconditions a storage hopper of smaller size corresponding toapproximately 1 hour of recording will be found to be sufficient. Anexample of use can therefore be as follows:

recording only from the beginning of a programme: the tape unwound bythe recording reel is taken up by the playback reel without filling thehopper;

before the end of the programme the user wants to playback the beginningof the programme without interrupting the recording: he stops theplayback reel and then puts it into fast reverse movement so as to sendthe recorded tape into the hopper 33 and re-reverses the direction ofrotation of the playback reel so as to begin playback at normal speed ornot with the possibility of reverse movement. The tape goes from therecording head into the hopper:

the user is interrupted by a telephone call: he operates a playbackpause and the playback reel stops. The tape continues to go into thehopper from the recording head;

the user wants to make up the time: he plays back the tape inaccelerated mode until the hopper 33 is empty and then he follows theprogramme live;

on the other hand the user wants to stop playback completely whilstcontinuing to record: he operates a "playback stop" control whichautomatically causes the deactivation of the playback head and theaccelerated rotation of the playback reel in the winding up directionuntil the tape is exhausted in the hopper 33 after which the recordingcontinues in the "normal" manner.

We claim:
 1. Apparatus for recording and playback, of a recording tapesuch as a video-tape recorder or tape recorder tape, With which playbackcan be selectively carried out in three modes which are an immediateplayback mode, a simultaneous offset playback mode in which theapparatus simultaneously records on a first region of the tape and readsa second region of the tape, which is at a distance from the firstregion, and a playback alone mode, the apparatus comprising a recordinghead (9), means for having the tape (2) circulate in front of therecording head and from a recording reel (6) respectively, a readinghead (8), means for having the tape circulate in front of the readinghead towards and from a playback reel (7) respectively, both the headsbeing provided with means enabling them to be actuated independently ofeach other, a storage hopper (33), located operatively between the twoheads (8 and 9) for receiving and storing in loose and random folds atape portion corresponding to the distance between said first and secondregions of the tape, means for selectively actuating the reading headand selectively feeding the tape in forward and reverse in front of thereading head independently of actuation of the recording head, wherebyduring recording of the first region of the tape by the recording headthe second region of the tape can be selectively read by the readinghead and fed without being read, selectively with and without change ofthe distance between the first and second regions of the tape, fittingmeans (28) for a cassette (1) with two reels (6 and 7) each of which isassociated with one of the ends of the tape, the recording and readingheads being arranged so that each one cooperates with one of thecassette reels, one of which in operation constitutes the recording reeland the other the playback reel respectively, and means (3, 24 and 25)for bringing the tape into position in relation to the storage hopper(33) after insertion of the cassette into operational relationship withthe fitting means.
 2. Apparatus according to claim 1, characterized inthat it also includes rolls (18 and 22) with which the tape of theplayback reel (7) can be moved in reverse at different speeds towardsthe storage hopper (33) with or without playback of the said tape. 3.Apparatus according to claim 1, characterized in that the storage hopper(33) is in a vertical position and has an upper entry disposed betweenthe said reading head (8) and the said recording head (9).
 4. Apparatusaccording to claim 1, characterized in that the storage hopper (33) has,in the direction of the width of the tape (2), a dimension equal to thewidth of the tape.
 5. Apparatus according to claim 1, characterized bymeans (3 and 24 and 25) for detecting the exhaustion of the length oftape contained in the hopper (33).
 6. Apparatus according to claim 1,characterized in that the said means for bringing the tape into positioninclude means (24 and 25) for drawing a portion of the tape (2) into aloop towards the inside of the hopper in such a way that the saidportion of the tape enters and leaves the storage hopper by its entry.7. Apparatus according to claim 6, characterized in that the means fordrawing a portion of the tape include an idle roll (25) which can bedisplaced vertically on a carriage (24) so as to draw the tape (2) intothe operating position towards the inside of the hopper from the initialposition when the cassette is inserted.
 8. Apparatus according to claim7, characterized in that from a situation in which a reserve of the saidtape (2) is stored in the hopper (33), the idle roll (25) is used toindicate that the said reserve has been used up when it is stressed bythe tape towards the outside of the hopper.
 9. Apparatus according toclaim 1, characterized in that it includes revolution counters on theguide and drive mechanisms so as to know the size of the offset betweenrecording and playback.
 10. Apparatus according to claim 1,characterized in that the hopper is associated with means for carryingout a blowing or suction action on the random folds formed by the tape.11. Apparatus according to claim 1, characterized in that the storagehopper (33) has, for the tape, a relatively narrow entry/outlet openinglocated between the two heads (8 and 9) and associated with means (3 and24 and 25) for pre-engaging a loop of tape towards the inside of thestorage hopper (33).